Download to sketchbook: LaserBurn.zip
Required library (install in sketchbook "libraries" folder): traer.physics 3.0
Built with Processing
Use the mouse to burn the metal with a laser. Notice that the sparks, smoke, bright light, and hot traces on the metal are all distinct layers so that they can be drawn independently of one another. This allows these elements to be animated without having to redraw the underlying damage caused by the laser.